1. Field of the Invention
The present invention relates to new cationic azo dyestuffs especially useful for the coloration of acrylic fibers.
2. Description of the Prior Art
Numerous cationic azo dyestuffs of the diazahemicyanine type are already known (cf. K. Venkataraman "The Chemistry of Synthetic Dyes", Vol. IV, 1971, pages 188-201). These dyestuffs, which may be represented by the general formula: EQU [D.sup..sym. --N.dbd.N--B]A.sup..crclbar. (I)
in which D.sup..sym. represents a cycloammonium radical, B represents the residue of an aromatic coupling components such as a secondary or tertiary benzene amine, a phenol or a compound with an active methylene group, and A.sup..crclbar. represents an anion, may be prepared by the oxidizing coupling of a nitrogen-containing heterocyclic hydrazine with a coupling compound or by quaternization with an alkylating agent of an azo compound resulting from the coupling of the diazo compound of a heterocyclic amine with a coupling compound.